Improved understanding of how our coasts will evolve over a range of time scales (years‐decades) is critical for effective and sustainable management of coastal infrastructure. A robust knowledge of the spatial, directional and temporal variability of the inshore wave climate is required to predict future coastal evolution and hence vulnerability. However, the variability of the inshore directional wave climate has received little attention, and an improved understanding could drive development of skillful seasonal or decadal forecasts of coastal response. We examine inshore wave climate at 63 locations throughout the United Kingdom and Ireland (1980–2017) and show that 73% are directionally bimodal. We find that winter‐averaged expressions of six leading atmospheric indices are strongly correlated (r = 0.60–0.87) with both total and directional winter wave power (peak spectral wave direction) at all studied sites. Regional inshore wave climate classification through hierarchical cluster analysis and stepwise multi‐linear regression of directional wave correlations with atmospheric indices defined four spatially coherent regions. We show that combinations of indices have significant skill in predicting directional wave climates (R² = 0.45–0.8; p < 0.05). We demonstrate for the first time the significant explanatory power of leading winter‐averaged atmospheric indices for directional wave climates, and show that leading seasonal forecasts of the NAO skillfully predict wave climate in some regions.

中文翻译：

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大气指数在描述英国和爱尔兰近海定向波气候中的作用


更好地了解我们的海岸在一定时间范围内（几年至几十年）将如何演变对于沿海基础设施的有效和可持续管理至关重要。需要对近海波浪气候的空间、方向和时间变化有深入的了解，才能预测未来海岸的演变以及脆弱性。然而，近海定向波气候的变化很少受到关注，更好的理解可以推动沿海响应的熟练季节性或十年预测的发展。我们研究了英国和爱尔兰 63 个地点的近岸波浪气候（1980-2017 年），结果表明 73% 是定向双峰的。我们发现，在所有研究地点，六种主要大气指数的冬季平均表达与冬季总波功率和定向波功率（峰值谱波方向）密切相关（ r = 0.60-0.87）。通过层次聚类分析和定向波与大气指数相关性的逐步多元线性回归对区域近海波浪气候进行分类，定义了四个空间相干区域。我们表明，指数组合在预测定向波气候方面具有显着的技巧（ R ² = 0.45–0.8； p < 0.05）。我们首次证明了主要冬季平均大气指数对定向波气候的重要解释力，并表明 NAO 的主要季节预报巧妙地预测了某些地区的波浪气候。